Apparatus for treating chemicals.



I. D. SARTAKOFF.

APPARATUS FOR TREATING CHEMICALS.

APPLICATION FIL ED JUIIE 5, I917.

Patented Nov. 12, 1913.

3 SHEETS SHEEI I 9 vweutoz 3 'SHEETSSREE[ 2.

Patented Nov. 12,1918.v

J. D. SARTAKOFF. APPARATUS FOR TREATING CHEMICALS;

APPLICATION FLLED JUNE 5. I917.

J. D. SARTAKOFF. APPARATUS FOR TREATING CHEMlCALS.

APPLICATION FILED JUNE 5.1917.

Pafvntvd Nov. 12, 1918.

3 bHEETS SHEET 3 .qlil,

JACK D. SARTAKOFF,

Specification of Letters Patent.

FEE}.

or new Frees, 2r. '2.

MPABAT'CHS FOR TREATING GI-IEIEIGALS.

Patented Nov. 12, 1918.

Application filed June 1917. Serial E0. imam.

To all whom it may concern:

Be it known that I, JACK-D. SARTAKOFF, a

citizen of Russia, residing in thecity of New York, borough ofManhattan, county and State of New York, have invented a certain nen anduseful Apparatus for Treating Chemicals, of which the following is aspecification.

This invention is an apparatus for treating or manufacturing chemicals,and, while it is especially adapted for the manufacture of sodiumsalicylate, it is equally well adapted in the treatment and manufactureof analogous and 'difierent products. Its construction and operationwill be described more particularly in connection with the manufactureof sodium salicylate in accord- -ance with the well known Bayer process,but, as suggested, the description of its use in this process willsuggest its applicability to others.

As is well known, the Bayer process emhodies three main operations,viz., first, the production of sodium phenolate; second, the subsequenttreatment of the dried phenolate with carbon dioxid under pressure,whereby the sodium phenolate is converted into sodium phenyl carbonate,and, third, the subsequent heating, in the presence of carbon dioxid, ofthe sodium phenyl carbonate in an autoclave, whereby the sodium phenylcarhonutc is converted into sodium salicylate. ln carrying out thesecond operation, the healing conducted at diiierent temperalures andpressurcs for certain periods, both the temperature and pressure beinginr-roiucd as the process progresses.

The present apparatus embodies means for uiuomatically cputrolling saidtemperatures and pressures, and permits of the manufaclure of theproduct under consideration on an extensive commercial scale, and withgr at eiliciency and economy of operation. in hat a superior product isproduced, a comparatively small amount of manual labor is required, anda minimum amount of fuel utilized.

in the accompanying drawings l have illu trated the pref-erred practicalembodiment of my invention, hot it. will be under- ;--lood that varidoilu-r forms may he used, i.-ro'.'id-d they 'uuhody the distinguishingpr zipls-s and characteristics oi my appzu r nsuch as appear trom thehereinafter iii tailed descriptioi'i and appended claims.

In the accompanying drawings, Figure l is a longitudinal view of theapparatus, partly in elevation and partly in section.

Fig. 2 is a sectional elevation on line 22 of Fig. 1.

Fig. 3 is a view, partly in section andpartly in elevation, s owing, indetail, one form of thermostatic control which ma be employed inregulating the operation 0 the apparatus, and particularly incontrolling the temperature thereof, and

i is a cross-section on line'44 of Fig. 3.

Referring to the drawings, A is a heating furnace, exposed to the directheat of which is a metal tank or receptacle B, preferably of steel oriron, in which are-located a plurality of metal drums, preferablystationary, C, shown as three in number, although any desired number maybe used. Furnace A embodies the customary'elements, such as fuelcharging door a, grate bars 32, heating fine 0, icy-pass d, which have acommon exite to the stack, not shown, and damper f adapted to cooperateeither with the flue c or bypass d.

Tank B contains a suitable heat-transferring, liquid medium 1'),preferably a heavypetroleum. the boiling point of which is upward of 220degrees Centigrade. In order that the oil D in tank B may be kept at auniform temperature, provision is made for keeping the oil incirculation, and, for this purpose, 1 employ one or more pumps,preferahly of the Archimcdcan screw type, em-

hodyin g a casing y, and helical screw it, fast on a shaft i, rotatableby suitable gearing In order to, spread the oil as it emerges from thetop casing g, I may employ 3 bathsplato 7c.

The drums C, which may take the form of large pipes, are screwed attheir ends into metal heads Z, the peripheries of which are secured inthe brickwork of the furnace, as clearly appears in Fig. 2. tach of thedrums C is provided with a suitable agitator embodying a rotatable shaftin, having outstamling,r=1 lial arms a, lo the ends of which are allixedscraping bars 0 0. extending longitudinally of the drum, said scrapingbars having! I heir outer edges 'ircterubly serrated, as shown at pay).th so "rat ions of one our 0 iii-111;! slafSSLI-rcd with relation to thelions 7. of the other bar 0, Wherchvthe e uri'acc of the drum isthoroug. l

and their or swept. Shafts m are driven by means of beveled gears g,each of which has a cooperating driving gear main or power shaft 8.

' Each of drums C is provided with a valved inlet pipe at for liquid,and a valved inlet pipe at for a gas, such as carbon dioxid, there beinga main carbon dioxid pipe u for supplying the .carbon dioxid. lipes tand u have a common entrance 1: to the drum, whereby the liquid undertreatment may be admitted through pipe t, and the dried productobtained. therefrom treated with carbon dioxid introduced through pipeu. Intermediate T-shaped, tubular member 10, one leg w of which connectswith a-vacuum gage y, and the other leg in of which connects with avacuum gage y, the passage to the vacuum gage y being controlled by avalve a, and the passage to the vacuum gage 3 being controlled by avalve (1 Each of the drums C is also provided with a draw-oil pipe 6,having a closing cap 7. A vacuum main E is common to all the drums C,each of said drums being connected therewith through the medium of apipe I), in which is positioned a manually operated valve 0, whereby thevacuum can be shut oil from the drums as desired.

It is frequentlydesirable to cool the drums contents quickly, and, withthis object in view, the apparatus preferably embodies means. wherebythe oil or other heating medium D in tank B may be readily cooled orchilled. To effect this result, I employ means for circulating said oilthrough an exterior cooling apparatus, said appa; a'atus embodying arotar pump F, having a hot oil inlet d, exten ing to the bottom of tankB, the oil'outlet e from the pump being connected with a cooling coil G,having-anoutlet for cooled oil f leading'to the top of tank B. Coolingcoil G is contained in a casing g supplied with cooling liquid, such aswater, through pipe h and having an overflow i for the warm water.

In order tofully utilize the heat of the products of combustion, whichtheymay contain upon their escape from flue c or by-pass d, 1 positionat the end of the apparatus farthest from the source of heat, and inproximity to exit flue e, an evaporating or drying receptacle or chamberH, preterably extending transversely of the apparatus, said chamberbeing provided with an inlet 8, outlet 9, and agitator or stirrer 10, asshown. Chamber H may, if desired,'be connected with vacuum main E.

Having described the apparatus enerally, as embodied in Figs. 1 and 2,will now describe a most important feature of the apparatus, viz., thethermostatic means for controlling damper 7, said means being showndiagrammatically and in detail in r positioned on a.

pipes to and 'v is a double- K, which meshes ment of the furnace whichit is desired tokeep under control-is thedamper and the thermostaticapparatus embodies means'for operating this damper so that allows of thefree passage of the products'of combustioneither through heatmg flue c,or through by-pass d, dependingon the temperature which it is desired tomaintain in the drums C.

The prime mover of ,the thermostatic means is designated in Fig. 3 bythe referdrums may be kept conence character I, and may embody any wellI known form of thermostat. As hereshown, however, it'embodies twostrips of material k and. 10 having different coefficients ofexpansion;in the instance shown, is representing iron, while [a reprcsents lead,the lead having the higher coefiicient or" expansion. These strips aresecured together, preferably, by welding and, after being thus securedtogether, are bent into the general U-shape form, as shown. Thermostat Tis immersed in the oil D, see Fig. l, with the end of one leg of theUshaped portion of said thermostat fixedly secured to the top or coverof tank B, as at 10 while the other leg extends upwardly through aslotin said cover and is pivotally secured to a rack J, with whichmeshes a pinion y" fixed on shaft 7'2 Also fixed on shaft j is agearwith a second rack J Mounted onrack form of a pendulum pivoted to abracket Z on said rack and in electrical connection with an electricalcircuit L fed from battery Z With a constructioi'r organized asdescribed, it is apparent that, as the temperature of the oil Dincreases, the metals of which the thermostat prnd in accordance withtheir-well defined coefiicients of expansion, the lead or outer strip11: expanding with greater rapidity than the result that the free leglrwill approach the other leg thereof, and, in so by the arrow thereon.pinion 7" is rotated in a counter-clockwise direction, as shown by thearrow, carrying therewith gear K in the same direction, as noted by itsdirectional arrow. Moreover, rack J which is in mesh with gear K, willbe consequentlv moved tothe left, as noted by its directional arrow.carrying therewith the contact Z mounted thereon.

By this movement,

J is a contact Z, in the is composed will .ex-'

doing, move rack J to'the right, as noted rack K? in the same directionas that nor-' mally imparted by gear K to rack J liounted on rack K is acontact 5*. electrically connected to the source of electrical energy Zas shown, and the circuit L is adapted to be made or broken whenrelative nbvenient between the racks J and K so position pendulumcontact Z that it engages contact Z.

From the description of the apparatusthus given, it will be apparentthat the time train, operating through pinion M, moves rack K to theleft, as indicated by the arrow thereon, While rack 2 is moved in thesame direction by pinion K controlled by the heat of the oil bathoperating through thermostat I and intermediate mechanism. The parts areso organized, however, that the contact of rack is always in advance ofpendulum contact Z of rack J so that the circuit L is broken by thebridge between these contacts until pendulum contact Z, due totheforward advance of rack J catches up and engages with contact Z If it beassumed that the time train is so controlling rack K as to advance it tothe leftat a constant speed, it appears that the pendulum contact Z canonly become engaged with contact Z* on said rack by the raising of thetemperature of the oil bath to such extent as tomove rack J suiiicientlyforward to overtake said contact l Pursuant to one of the objects of theinvention, which is focontrol the raising of the temperature of the oilbath for predetermined periods of time, I utilize the coiiperating ac-'tion between the racks J and K for controlling the heat applied to theoil bath,

and, as this may be most readily accomlished through the manipulation ofthe eat-controlling damper f, provision is made to govern the operationof' said damper through the operation of electrical circuit L,controlled by contacts Z and Z In circuit L is included anelectro-magnet L, the armaturel of which carries, and is insulated from,a stem L on the lower end of which is formed a needle valve n. Stemsured at all times, it being manifest that,

If projects into a container 1?, in the bottom of which is a valve seatcontrolled by needle valve 71- of said stein. Fluid, such as water, isfed into container Nthrough an inlet 71 and may be kept at a constantVolume by means of a suitable overflow pipe a However. if desired,overflow pipe n may-be dispensed with and the level of liquid Withinsaid container may be controlled by any well known formof float valve.

Communicating with the outlet of container N is d pipe n, the oppositeend of wh ch is so positioned as to discharge liquid flowingtherethrough into a receptacle or bucket O. Bucket O is suspended fromsabail, to which is secured one end ofa chain or cable a which passes oversuitably disposed direction rollers 0 and is secured at its opposite endto damper f, which controls the passage of the products of combustionthrough heating fine 0 or by-pass rl.

The weight of the empty bucket Oiand its adjuncts hereinafter described,is less than the weight of damper f, so that said damper normallygravitates into a position to leave heating due 0 open and to closeby-pass 1].

If, however, the water in container N is allowed to flow through pipe nand into bucket 0, it being' assumed that the bucket is closed, theweight of said water will be suliicient to over-balance the weight ofdamper 7, thereby causing it to be raised to close carried out throughthe energization of magnet L, \l'lilCl'l attracts its armature L therebylifting needle valve n and allowing of.

flue c and open by-pass cl. This operation is Magnet L has the furtherfunction of controlling the retaining of the water within bucket 0,since, as clearly shown in Fig. 3, armature L of said magnet, when themagnet is deenergized, rests upon a pair of spaced contacts 42 12 whichform the terminals of an electric circuit P in which is included anelectro-magnet P. Armature 79 of said electro-magnet P is secured to thestem 19 of a needle valve 72 for controlling. an outlet aperture 7) inthe bottom of the bucket. When armature L is in a position to bridgecontacts 37 and p magnet P is energized and needle valve 77 moved to aposition to open outlet aperture 9 and allow the water to flow from thebucket into a sink Q positioned immediately therebeneath. However, whenmagnet L is energized, its armatiire L is lifted free from contacts 197), magnet l? is thereby deenergized, and needle valve .79 gravitatesinto a position to seal outlet'aperture 79". By virtue of'the fact thatthe flow of water into the bucket and the dischar e of said Watertherefrom are controlled through unitary means, viz., armature L propercoordination between these operations is asat a constant level withinthe bucket, the superfluous water overflowing into sink Q. Moreover,magnet L has the further function of controlling the discharge of Waterfrom bucket 0, since, as soon as said magnet 18 deenergized, itsarmature L will fall and bridge contacts p and 72 thereby completing thecircuit through magnet P for the purpose of elevating needle valve 12and opening the outlet 77, whereupon the described.

. operation ,is efiected at a temperature, e. 9.,

90 degrees centigrade', at which the thermo-' static apparatus 0 is notparticularly affected. Said apparatus may, however, be employed, ifdesired, to so control the heat supplied to the bath D during the dryingoperation that the material within the drums C will not be over-heatedor burned. When, however, it is desired to increase the temperature ofthe oil bath, say to 150 degrees centigrade, such elevation intemperature results in' the active operation of rack J sodium phenolateis fed into drums 0.

through their respective inlet pipes t. The furnace having beenpreviously started, and

i the oil bath heated to the desired initial temperature, with thedamper f in lowered position, the vacuum isapplied to vacuum main E andthe agitators within the drums set in operation. As the result of theheat, partial vacuum and agitation, the liquid is -quickly concentratedand eventually evaporated to complete dryness within the drums. Assumingthat the temperature at which the material finally dried is somewhathigher than that at which it i desired to effect the carbonating of thedry sodium phcnolate, the temperature of the oil bath may be quicklyreduced to the desired degree by means of the oil circulatory apparatusdescribed, embodying pump F cooling coil G and appurtenances. Assuminthe required temperature in the drums 6 has been obtained, and that itis desired to begin the carbonation treatment, the valve 0' having beenpreviously closed to shut off the vacuum, carbon dioxid is admitted tothe apparatus by opening valved pipe 24, the de sired pressure beingobserved through pressure gage 3 As a general rule, it not necessary toemploy the thermostatic regu lating apparatus during the dryingoperation described, and, in order to render said thermostatic apparatusinoperative, there is included in circuit L a manually operatedcommensurate with the action of thermostat 1. During this operation bythe thermostat, the time train is operating either at constant orintermittent speed, as the case may be, to advance rack K at such-speedas-is calculated to produce a number of degrees rise in temperaturethrough the predetermined period. The operations of rack K successivelycarry contact Z in a direction away fom pendulum contact Z, and, sincedamper f is in a position to allow '01 the heating of the oil bath D b"the hot products of combustion passing trough flue c as long ascontacts Z and Z are free from engagement with one another, it willappear that, as contact Z moves away from contact Z, the oil bath D willbe constantly raising internperaturc. When this temperature arrives atsuch a point that the operation of thermostat'I, acting throughintermediate connec- Lions with rack J will cause contact ZPto overtakeand engage with contact Z, circuit L will be completed, thereby liftingarmature L of magnet L, breaking circuit P to allow of the seating ofneedle valve 12 and raising needle valve or to allow the water to runfrom container X into bucket O. The introduction of this water in bucket0 results in the over-balancing of damper f, and causes the same to beelevated to close heating fine 0 and shunt the hot products ofcombustion through by-pass d. With this condition of the parts, afurther elevation in temperature of the oil bath D will cease.

- If the time-train is operating intermittentlv. the engagement ofcontact Z with contact Z will continue through the period of rest ordwell of rack K or until said rack again starts to move forward. -However, if the time train is operating at eonstant speed, it will, in avery short time, move contact Z tree from contact Z, and, by so doing,release armature L with the result that needle valve n will sealcontainer N, the circuit P being simultaneously ener ized to lift needlevalve 39 and allow of t e draining ot' bucket As soon as bucket O isdrained, its weight ceases to he sufiicient to over-balance damper f,and the latter gravitates to a position to close bypass (I and openheating-flue c. This having been accomplished, the hot products ofcombustion will immediately course through the heating flue and serve tofurther raise the temperature of the oil bath I), this elevation intemperature resulting inthe further operations on the part of thethermostat to advance contact Z sufi iciently to catch u and engage withcontact 7;, whereupon circuit L is completed and the operations ofclosing and subsequently opening the damper, hereinbeiore described, arerepeatcd.

In this manner, the heating of the Oil bath progresses in successivestages until the temperature has, attained a predetermined maximum. atwhich time contact Z will come into engagement with a fixed contact Z inelectrical connection'with a branch of circuit L. Contact Z has nomovement, and, since the engagement of contact Z with contact 1immediatel precludes further heating it is manifest that "a further risein temperature of the heating bath D will be impossible. This is becauseofthe fact that, as soon as contact Z comes into engagement with contactZ, the damper will shunt the hot roducts of combustion through lay-passd. The time train may, of course, continue to operate rack K aftercontact Z" has nassedthe fixed or stationary contact Z". but, after thishas occurred, said contact Z will have passed out of the range ofoperation of pendulum contact Z .and will have no further cooperationtherewith.

Contact Z has been described as stationary or fixed. but it will beunderstood that this terminology is to be construed as meaning that itis not moved or mechanically actuated' from the operating parts of thethermostat or time train. It may be manually adjusted to differentpositions with relation to the travel of contact Z in accordance withthe predetermined maximum degree.

of heat desired. I

As has hercinbefore been pointed out, time train driven rack K may beactuated continuously or intermittently, as required. If it is desiredto heat the material in tank C- to a gradually and continuouslyincreas-. ing temperature. the time train will, naturallv. be actuatedcontinuously: if. however, fill it is desired to i crease temperaturesat successive stages, and to maintain said tempera tures for definiteperiods of time, then the time train will be driven intermittently. 2'.12., will have times of dwell depending on the 6 length of the periodsat which it is desired a plurality of drums. means to lree the materialat a certain tempera.- ture or each of the successive periods.Clock-driven mechanism of the two types described, however, is so Wellknown that any further reference thereto is not deemed necessary oradvisable. As heretofore suggested, asthe temperature at which thematerial is treated Is increased during the successive stagcs'oftreatment, the pressure of carbon dioxid is also increased, and-thispressure is, preferably, maintained constant at any of the successivestages of treatment. That is to say, where the temperature is maintainedconstant for a given period, a certain pressure is employed, whereas ata successive period, where the temperature is increased, the, I pressureis also increased, but maintained constant for said period of constanttemperature. Thus, e. g., the temperature of carbonation may begin atdegrees centigrade, whereas the final conversion of the carbonate intosalicylate of soda may take place at 200 degrees centigrade, this matterof temperature beina continued for quite a prolonged period. Thepressure, on the other hand, may begin at 25 pounds and graduallyincrease, during the several successive changes in temperature, up to150 pounds. it will be understood that changes and departures in theapparatus as described, as well as in the specific procedure outlined,may be made without departing from the i spirit of the invention, sofaras concerns 1 the apparatus, the scope of which is coextensive withthe appended claims.

Having thus fully described the invention, what I claim as new anddesire to secure by Letters Patent, is:

1. In an apparatus for treating chemicals, a plurality of drums. meansfor heating the drums, and means for automatically regulating theincrease in temperature within the drums at predetermined periods.

2. In an apparatus for treating chemicals, a plurality of drums, meansfor heating the drums, and means for automatically regulating theincrease in temperature within the i drums at predetermined periods andmainllb taining the temperatures substantially constant between thesuccessive periods.

3. In an apparatus for treating chemicals, a plurality of drums. meansfor heating the drums, means the increase in temperature within thedrumsat predetermined periods, and means for applying gaseous pressure to thedrums.

4. in an apparatus for treating chemicals, 4

for heating the 125 drums. means for automaticallyregulating theincrease in temperature withinthe drums at predetermined periods andmaintaining the temperatures substantially constant hetween thesuccessiveperiods, and manually 13 for automaticallvregulatingcontrollable: means for applying increased controlled means forincreasing the pressure in the drum at each of the successive periods.7. In an apparatus for treating chemicals,

' a heating drum, an oil bath cooperating with said drum for heating thesame, means for .heatingthe oil bath, a thermostat for controlling theheating means, and a moving element controlled by a time traincooperating with the thermostat whereby the temperature of the oil bathmaybe increased at predetermined periods.

8. In an apparatus for treating chemicals,

- a=heating drum, an oil bath cooperatingwith said drum for heating thesame, means for heating the oil bath, a thermostat for con trolling theheating means, anda moving element controlled by a time traincooperating with the thermostat whereby the temperature of the oil bathmay be increased for successive periods and kept constant between eachof the periods.

9. In an apparatus for treating chemicals, a heating drum, a chamberadapted to contain a heat-transferring medium for heating said drum,means for circulating said heattransferring medium whereby itstemperature is kept uniform, and means for cooling said medium.

10. In an apparatus for treating chemicals,

a heating drum, a chamber adapted to containa heat-transferring mediumfor heating said drum, means for circulating said heat-transferringmedium whereby its temperature is kept uniform, and means forcirculating said medium'exteriorly of the chamber-through arefrigerating means whereby the medium is cooled.

11. In an apparatus for treating chemicals, a heating drum, means forheating the same, means for automatically regulating the temperature ofthe heating means, and an agitator in said drum-adapted to scrape theinner surface thereof, the scraping edge of' said agitator beingserrated.

12. In an apparatus for treating chemicals, a heating drum, means forheating the same, means for agitating the contents of the drum, vacuummeans connected with the drum, ani inlet and an outletto the drum forthe material being operated upon, and means for introducing carbondioxid into the drum.

13. In an apparatus for treatin chemicals, a heating drum, a liquidbathor heating said drum, means for automatically increasing the temperaturethereof at predetermined, successive intervals, means for circulatingthe liquid bath whereby its tem-' perature is maintained substantiallyuniform, and means for circulating the liquid bath exterior ofthe drumthrough a cooler.

14. In an-apparatus for treating chemicreasing the temperature thereofat prede- I termined, successive intervals, means 'for' circulating theliquid bath whereby its temperature is maintained substantially uniform,means for circulating the liquid bath exterior of the drum through acooler, an agitator within the drum, and means for introducing carbondioxid within the drum.

16. In an apparatus for treating chemicals, a heating drum, a liquidbath for heat ing said drum, means for automatically increasing thetemperature thereof at predetermined, successive intervals, means forcirculatin the liquid bath whereby its temperature 1s maintainedsubstantially uniform, means for circulating the liquid bath 1 exteriorofithe drum through a cooler, an

agitatorwithin the drum, means for in. ,troducing carbon dioxid withinthe drum,

and means for creating a partial vacp um within the drum.;

17. In an apparatus for treating chemicals, a chamber adapted to containa liquid heat-transferring medium, a plurality of drums exposed to theheating action of said medium, a furnace for heating the chamber, aheating flue and a by-pass for said furnace, means for directing thepassage of the products of combustion either through the fiue or theby-pass, and automatic means, cooperating with said directing means forclosing off theproducts of combustion from the flue and directing themthrough the bypass when the heat-transferring medium in the chamberattains a predetermined degree.

.18. In an apparatus for treating'chemicals, a chamber adapted tocontain a liquid heat-transferring medium, a plurality of nuns exposedto the heating action of said medium, a furnace for heating the-chamber,

a heating flue and a b -pass for said furnace, means for. dircting t epassage of the products of combustion either through the flue or theby-pass, automatic means, coiiperatmg with said directing means, forclosing off the products of combustion from the flue and directing themthrough the by-pass when the heat-transferring medium in the chamberattains a predetermined degree, said latter means embodying a bucketcoperating with said controlling means and adapted, when a fluid Weightis added thereto, to shut 0d the products of combustion from the heatingflue, and thermostatic means automatically controlling the infl w ofwater to said bucket. f

19. In an apparatus for treating chemi cals, a plurality of heatingdrums, a liquid heat-transferring bath for heating said drums, a furnacefor heating said bath, said furnace being provided with a heating fluethrough which the products of combustion pass to heat the bath, and aby-pass through which the products of combustion pass directly to thestack, and a damper normally closing the by-pass'but adapted to open theby-pass and close the heating flue when a suitable, cotiperatingcounter-balance is brought into operation, in combination withthermostatic means and intermediate mechanism for operating saidcounter-balance when the temperature of the heat-transferring bathattains a predetermined deree. 20. In an apparatus for treatingchemicals, a heating drum, a liquid bath for imparting heat to saiddruuit means for heating the liquid bath, means for regulating thetemperature of said heating means, and thermostatic mechanism,controlled by a time train, coiiperating with said temperatureregulating means, for automatically and successively raising the liquidbath to predetermined temperatures.

21. In an apparatus for treating chemicals, a heating drum, a liquidbath for imparting heat to said drum, means for heating the liquid bath,means for regulating th tein erature of said heatin means andthermostatic mechanism, controlled by a time train, coperating with saidtemperature regulating means, for automatically and successively raisingthe liquid bath 0 predetermined temperatures, and maintaining the liquidbath at a substantially constant temperature for a succession ofpredetermined periods.

In. testimony whereof I have signed my name to this specification.

JACK D. SARTAKOFF.

